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Finding the Fourth Proportional to 812.24, 1,120.63 and 480.78

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Solution

The fourth proportional to 812.24, 1,120.63 and 480.78 is: 663.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.24 : 1,120.63 = 480.78 : x
  2. Step 2: Convert to fraction form
    812.24/1,120.63 = 480.78/x
  3. Step 3: Cross multiply
    812.24x = 1,120.63 × 480.78
  4. Step 4: Simplify right side
    812.24x = 538,776.49
  5. Step 5: Solve for x
    x = 538,776.49/812.24
  6. Step 6: Final answer
    x = 663.32

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Half scale
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Double scale
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.